The brief
The Sharan, a heavy family MPV, had developed clunking over bumps, the front tyres were wearing unevenly, the car was pulling to one side, and there was a vibration through the steering. Those are the signs of worn front lower arms. The front lower arms locate the bottom of each front wheel and hold it at the angles the geometry is set to. They pivot on rubber bushes and a ball joint, and when those wear out they stop absorbing impacts and holding the wheel steady. That extra play is the clunk over bumps, the vibration and the pull as the geometry wanders, and uneven tyre wear because the wheels aren't sitting where they're aimed. On a car that carries weight, those parts work hard and wear out, and once they do the handling and the tyres pay for it.
The diagnosis
A pry-test on both front lower arms confirmed it: the bushes were deflecting past the service limit and the ball joints had play, with visible cracking in the rubber, on both sides. One arm was no better than the other. When both arms are tired together you do them as a pair. Fitting one fresh arm against an old one leaves a stiffness mismatch front to front, and you'd be back to do the second soon anyway, so it was both arms, with a four-wheel alignment after to reset the geometry on the new parts.
The work
Both front lower arms came off, and a matched pair of genuine VW-spec replacements went on with new bushes and ball joints, every fastener torqued to the manual figures. Then the car went onto the alignment rig for a four-wheel set-up. A road test confirmed the clunk was gone, the pull was gone, and the steering had firmed back up.
The outcome
Knock gone, no pull, steering tight again, and the alignment back on spec, so the front tyres will wear evenly. The Sharan went home with the front end behaving the way it should. Lower arms carry the front geometry, and once their bushes and joints wear the handling drifts and the tyres pay for it, so a fresh matched pair and a reset alignment put it all back where it belongs.